1. Field of the Invention
The present invention generally relates to electromagnetic reciprocating pumps and, more particularly, is directed to a closed type electromagnetic reciprocating pump for use in suction and discharge of solvent, chemical and so on.
2. Description of the Related Art
As described, for example, in Published Examined Japanese Patent Application No. 57-30984, a fundamental arrangement of conventional electromagnetic reciprocating pump is known. This conventional electromagnetic reciprocating pump is composed of a piston which is reciprocated by an alternate action of a magnetic action and a spring action and a cylinder which defines a working chamber together with the piston, and a suction opening and a discharge opening are provided on the cylinder or the suction opening is provided on the piston and the discharge opening is provided on the cylinder.
The conventional electromagnetic reciprocating pump is suitably applied to gas and cannot be used for pumping liquid without difficulty from a configuration standpoint. Further, since the conventional electromagnetic reciprocating pump is arranged such that the piston is brought in direct contact with fluid, the conventional electromagnetic reciprocating pump cannot be applied to corrosive fluid irrespective of gas and liquid without difficulty. There is then the problem that the application range of this electromagnetic reciprocating pump to a wide variety of fluids cannot be extended.